Portable invalid wheelchairs



y 6, 1969 K. GARDNER ET AL 3,442,532

PORTABLE INVALID WHEELCHAI RS Filed May 1, 1967 Sheet I of 4 INVENTORSDona/d A. W/ [#0130 (Kt/mef/i 6' onar May 6, 1969 GARDNER ET AL3,442,532

PORTABLE INVALID WHEELCHAIRS Filed May 1, 1967 Sheet 2 of 4 y 1969 K.GARDNER ET AL 3,442,532

PORTABLE INVALID WHEELCHAIRS Filed May 1, 1967 Sheet 4 3 of 4 y 6, 1969K. GARDNER E 3,442,532

PORTABLE INVALID WHEELCHAIRS Filed May 1, 1967 Sheet 4 of 4 UnitedStates Patent C) U.S. Cl. 280250 Claims ABSTRACT OF THE DISCLOSURE Acollapsible wheelchair in which relatively small ground wheels areconnected by chains to handwheels to permit driving. The wheelchair isformed by upper and lower mutually pivoted frames that are each unitaryand permit vertical collapsing.

The present invention relates to vehicles travelling upon horizontal andinclined substantially smooth planes. More specifically the inventionrelates to invalid wheelchairs with particular emphasis on theirimproved capability to negotiate successfully in domestic and publicenvironments both indoors and out. Furthermore the invention includesimprovements in foldability and portability.

A study of wheelchair designs over the last hundred years has revealedthe discarding of numerous configurations and the gradual evolution of afoldable wheelchair which was influenced largely by the advent of theautomobile as an indispensable means of transportation. For many yearsnow, almost all wheelchairs have been of one basic configuration. Theycomprise two large diameter main wheels and two smaller castoringwheels, a frame which folds across the main axle line and a seatingmeans comprising a flexible material slung laterally between the twoside frame structures. Manual propulsion is achieved by the spasmodicgripping and releasing propelling rims which are concentrically mountedupon the large diameter wheels.

Most wheelchairs serve as wheeled vehicles for both indoor and outdooruse. Because of this dual purpose, they are by no means ideal foreither. We believe that by our analysis of the problem a newconfiguration has been found which makes the wheelchair more suitablefor its many contemporary roles. The standard propulsion methodcurrently achieved by the large diameter rims, although as simplemechanically as one could hope to design, is not necessarily the idealsolution. In view of technological progress over the last twenty orthirty years, simplicity is no longer the criteria. An examination ofwheelchairs in the English magazine Design of August 1962 was made byNurse Raynor. In this article the Very fundamentals of the design,namely the seating and the method of propulsion were questioned. Thesetwo fundamentals are interrelated.

Because of the large propelling wheels on conventional wheelchairs, theonly practical way for compact collapsing is to bring the two sidestructures together laterally. In such collapsing, the seat is laterallyfolded. This is made possible by the use of a flexible slung fabricseat. Such a seat is considered the least desirable by all professionalpeople concerned, even for able bodied individuals. Notable referencescan be found in the publications Anatomical Physiological andAnthropometric Principles in the Design of Ofiice Chairs and Tables andMeasurements for Comfortable Sitting and the article in Design of August1962 by Nurse Clare Raynor. A few manufacturers provide a firm, hingedor removable upholstered seat portion in an attempt to overcome theobjection cited. In other cases the owner improvises with varyingdegrees of success. To our knowledge, however, the back remains as aflexible slung fabric support on the majority of conventionalwheelchairs.

The classical means of propulsion i.e. by directly driving the mainwheels manually, is highly unsatisfactory for the following reasons:

(a) The occupants knuckles are easily barked when negotiating confinedspaces such as doorways.

(b) Dirt adhering to the tires is transferred to the occupants hands.

(c) A reciprocating discontinuous drive is unavoidable, making progresson the level for any distance extremely laborious, and the slightestincline almost insurmountable.

(d) The position of the rim forces the occupant to take an unnaturalposture which hampers circulatory, respiratory, and digestive functions.

(e) The large diameter wheels control the frame configuration, theseating configuration and dictate the method of collapsing.

(f) A custom seating design (frequently necessary having regard todeformities and the like in the user) becomes a major modification ofthe frame and is again dictated by the large wheel diameter.

(g) The footrest area is condensed if the frame is folded laterally andits design is restricted accordingly.

(h) The large wheels have a rearward overhang which hampersmanoeuverability.

(k) A separate brake required for each side of the chair since a crosslinkage would prevent folding.

(l) The large diameter of the rear driven wheels dictate closerproximity to the front wheels in terms of ground point contact than isthe case with the herein disclosed chair, and consequent relativeinstability.

The current method of propulsion demands large diameter wheels andlaterally folding arrangements (i.e. a structure in which the two sidescome together normal to the direction of wheelchair travel) whichimposes severe restrictions on the seating and overall design.

An objective of the invention is therefore to provide a wheelchairconfiguration capable of meeting the following parameters without theloss of the conventional wheelchairs versatility, serviceability andsafety, manoeuverability, reliability or convenience. These parametersare as follows:

(a) Width not exceeding 25".

(b) A substantial weight and collapsed volume reduction.

(c) Manoeuverability and stability as good or better than conventionalwheelchairs including the elimination of the rearward overhang.

(d) A propulsion system wherein the occupant is not required to exertexcessive force in negotiating normal inclines associated with theaverage outdoor environment.

(e) A continuous rather than a spasmodic form of propulsion, havingtherapeutic value.

(f) A means of providing rigid or semi-rigid seating designed within therecommendations of the medical profession and freedom within the designfor modifications of the seating to suit individual requirements withoutinterfering with the fundamental configuration of the chairs structure.

(g) To provide a means for propulsion that will not injure or soil theoccupants hands and one to be broad enough in its concept to serve awide variety of disabilities.

(h) Considerably greater stability against overturning due to the longerwheel base made possible by the use of relatively small diameter frontand back wheel-pairs.

Some further important novel features of the present invention reside inthe provision of a chair which is collapsible vertically downward incontrast to laterally, and includes a seat and a back which move fromthe usual angular relationship into a final, horizontal, co-planar,coterminous relationship with an approximately equal overhang, (for theseat-back combination) beyond the pair of front and back wheels, withthe ends of the seat-back combination in the collapsed positionconstituting substantially the outside chair-length, in virtue of whicharrangements, upholstering of the back and/or seat is rendered possible,while impractical with laterally folding chairs; and all the foregoingin combination with a chair which, when collapsed is only some 12 incheshigh to the upper plane of the collapsed back and seat, so that thechair may be pulled by the user-occupant after him following histransfer from the chair to the drivers seat of a Volkwagen or the like,onto the passenger seat beside him, the invention also importantly,featuring upper and lower mutually pivoted frames each of which isunitary, and does not change its profile as between the in-use andout-of-use positions, so that it is as strong and rigid when collapsedas it is when extended. As a result, the chair is not liable to becomeloose and weak with repeated opening and collapsing due to having amultiplicity of pivoted joints, which of course is of the very essencein such chairs. In addition, the chair can be moved by the user betweenopen and collapsed positions with one hand only. Further it will nottend to roll-away during transfer of the patient due to the novelparking brake means disclosed. It can easily be folded and then rolledunder beds or the like, and lends itself readily to shipping andhospital stacking.

With the foregoing in view, and such other object, purposes oradvantages as may become apparent from consideration of this disclosureand specification, the present invention consists of the inventiveconcept embodied in the method, process, construction, arrangement ofparts, or new use of the same, as herein particularly exemplified in oneor more specific embodiments of such concept, reference being had to theaccompanying figures in which:

FIGURE 1 is a perspective view of our wheel chair in its upright oroperating position.

FIGURE 2 is a perspective view of the two fundamental frame componentsshowing their respective relationships.

FIGURE 3 is a perspective view of the stay frame and propulsionsub-assembly.

FIGURE 4 is the side elevation of the wheelchair in its upright oroperating position.

FIGURE 5 is the elevation of the wheelchair in its partially collapsedcondition.

FIGURE 6 is the elevation of the wheelchair in its fully collapsedcondition.

FIGURE 7 is a side elevation showing the basic frame elements in thedistended mode.

FIGURE 8 is a fragmentary side elevation showing an alternativeconfiguration for the arm rest.

FIGURE 9 is a side elevation showing the basic frame elements in thecollapsed state.

FIGURE 10 is a sectional view taken on line 10-10 on FIGURE 4.

FIGURE 11 is a diagrammatic side elevation of an alternative wheel chairconfiguration having the driving wheels at the front of the chair.

FIGURE 12 is a diagrammatic side elevation showing the alternative wheelchair configuration in a partially collapsed position.

FIGURE 13 is a diagrammatic side elevation showing the alternative wheelchair configuration in the fully collapsed position.

FIGURE 14 is a fragmented perspective showing the jacking method ofbraking.

FIGURE 15 is a partial side elevation showing the jacking method ofbraking.

FIGURE 16 is a fragmented perspective illustrating the latching meansfor maintaining the chair in the extended osition.

FIGURE 17 is a section taken on line 17--17 of FIG- URE 16 showingdetails of the latching mechanism.

FIGURE 18 is a detail of FIGURE 17 viewed on arrow X.

FIGURE 19 is a cut-away elevation of the chain-locking method ofbraking.

In the drawings, like characters of reference designate similar parts inthe several figures.

Description of construction With reference to FIGURES 1 and 2, ourwheelchair comprises a seat 1, a back rest 2, a pair of arm supports 3,an upper frame collectively designated 4 comprising principally the sidemembers 5, a lower cross brace 6 and an upper cross brace 7 (immediatelyagainst the rear seat edge in the position of FIGURE 4), a lower framecollectively designated 8, a foot rest assembly 9 spanning the lower endof the upper frame 4, a pair of castoring wheels 10 attached to thelower frame 8 near the front end thereof, a pair of driven wheels 11located near the rearward end of the lower frame 8 and a pair ofpropulsion assemblies generally designated 12 located in the area belowthe arm supports 3.

The design of the frame is governed by the requirement forcollapsibility into the smallest practical package. We have imposed alongitudinal limit to this package as being substantially the sum of theback-to-front seat depth plus the back rest height, when the rear andlower edges thereof respectively are contiguous, (see FIGURE 6). Thisrequirement has largely dictated the concept of collapsibility used.

It will be seen in FIGURE 7 that frame members 5 have a characteristicprofile which is described by the interrelationship of points designedA, B, C, D and E.

The starting point in the design of the frame is length CD. This has tobe adequate in length to support the seat, but no longer than isnecessary since in the collapsed condition excessive length increasesthe collapsed package height as shown in FIGURE 9.

The anthropometrics must then be considered in terms of the arm restposition relative to the seat and thus the length DE is established. Theangle CDE is also determined by anthropometric considerations.Professional recommendations are that this should be slightly greaterthan the right angle, for example,

The collapsed package, FIGURE 6, shows that the seat 1 and the back rest2, fall into a common horizontal plane, the side edges of the seat beingsupported by the runs 5A of frame members 5, between points BC, and theback rest side edges at point C and E. It therefore follows that theangle BCD on FIGURE 7 is established by projecting a line t1-t2 throughpoints E and C downwardly and forwardly towards the footrest area. Atthe upper corners of back rest 2, a pair of handles 5B is provided, andat this point it should be noted that braces 6 and 7 are welded solidlyto the side members 5.

If desired the run DE may be shortened as in FIGURE 8 to provide acurved arm rest 3 of the same effective height as to the support portionthereof.

The arm supports 3 are preferably integrated into a single U tubeassembly 14, FIGURE 2 which is pivotally mounted upon the uppermostextremities of frame members 5. The transverse portion 15 of the armrest assem bly 14 supports and guides the back rest 2. To prevent theback rest 2 in FIGURE 4 from falling forward, a pair of elongated openguideways 16 are secured to the rearward face of the back rest, 2, asshown in FIGURES 4 and 5, trapping member 15 in juxtaposition with saidback rest but permitting sliding relationship therewith.

A reference line w1-w2 on FIGURE 7 drawn horizontally through point Band consequently .parallel to a ground reference plane gl-g2, shows thatthe slope of plane t1-t2 (through points BC and E) is inclined to thehorizontal ground reference at an angle CBw2. It is desirable that pointD on frame 4 should overlieand be supported upon point F of the lowerframe '8. Ittherefore follows that the arc through which point D passesin the collapsing movement must be that of angle CBw2. This then governsthe selection of pivot point on frame 4 (by which frames 4 and 8 arerotatably connected) between points A and B, the angle of bend B, namelyangle ABC, and the inclination of frame 8 relative to the ground planeg1-g2. It will be noted that this rearward inclination of frame 8 iscompatible with about an eleven or twelve inch diameter driven wheel 11and an eight inch diameter castor 10. See FIGURE 9.

When the chair is extended, occupant-containing position, the frames 4and 8 are held in rigid relationship by strut means in the form of apair of stayv frames which are actually elongated gear casescollectively designated 17, and best illustrated in FIGURE 3. These.pivot at their lower ends 18 upon and about the axles of wheels 11. Atubular tie bar 19 maintains them in parallel relationship and extendstransversely beneath the seat 1 between points C and D of frame 4,FIGURE 7.

Tie bar 19 is attached to seat 1 by a pair of flat brackets 20 whichextend downwardly therefrom. (being secured to the seat edges) andthrough which said -tie bar 19 freely extends as shown in FIGURE 10,such that there is a sliding clearance for frame members between theunder side of the seat 1 and the upper side of tie bar 19. The back ofthe seat 1 is hinged to the lower corners of the back rest 2 at 21 asshown in FIGURE 4. It will therefore be apparent that as the chaircollapses, the seat and back rest assembly are drawn downwardly andforwardly over the profile of frame 5. Shortly after the hinge point 21passes over point C (FIGURES 5 and 7) of the frame 5, the back 2 andseat 1 fall into a common plane, overlying portion B, C and E whichreaches the horizontal in the final or fully collapsed position bestillustrated in FIGURE 6. This action is the essence of compact foldingsince the upper edge of the back rest 2 in this position is in closestpossible proximity to point B of frame 5 and prevents a substantialspace-consuming overhang beyond point B.

Arrn supports 3 are pivotally connected to linkages 22 (FIGURES 5 and 6)which in turn pivot at their lower ends about points 23 (as best shownin FIGURE and the linkages 22 are herein considered as part of thecomplete arm rest assemblies 14. The rear ends of the arm supports 3 arepivotally connected at 24 which are coincident with points E on framemembers 5 (see FIG- URE 7). Thus, as the frame is collapsed the armsupports 3 and the linkages 22 combine to draw the arm supports intoline with the seat and back upholstery as the tie bar 19 (FIGURE 10)moves away from the point E on frame 4. This process is illustrated byreading FIGURES 4, 5 and 6 in sequence. To look the chair in thecollapsed position (FIGURE 6) the operator may apply downward handpressure to the arm supports 3 and thereby force them to over-toggle intheir relationship to linkages 22.

The chair is latched in the extended (occupying) position by means of apair of flat, rearwardly extending tongues 32 (FIGURE 16) attached toeach rear corner of seat 1. A single aperture (32A) in each tonguebecomes aligned with the axis on arrow 17-17, of upper brace 7 when thechair is fully extended. Within and projecting from the ends of brace 7(FIGURE 17) is a pair of plungers 33 both outwardly spring biased andjoned by a flexible tape 34 which is substantially held in tension bythe bias of the springs 34A bearing against the fixed, apertured,stop-washers 343. When the said plungers project through tongues 32, thechair seat 1 is prevented from sliding forward or rearward with respectto frame 4. An actuating knob 35 located centrally on brace 7 isconnected to a stub-shaft 36 having a transverse open slot 36A thereinthrough which tape 34 passes. A partial turn of knob 35 winds tape 34around stub-shaft 36 thus drawing both plungers 33 inwards andwithdrawing them from 6 inlgigement with tongues 32 thus allowing thechair to The driving means (best illustrated in FIGURES 1 and 3)comprises a pair of handwheels 25 each having an integral sprocket 26and a chain 27 within each of gear cases or struts 17, connecting saidsprocket 26 to a lower sprocket 28 attached to a driven wheel 11. Thestay rames 17 each comprise essentially a pair of tubes 29 welded toupper and lower mounting plates 30 and 31 through which the chain drivepasses in order to provide a clean safe protective guard for said chain.Incidentally, the handwheels 25 may readily be lowered from the locationshown and positioned lower down, so that they do not project upwardly inthe collapsed position as indicated in FIGURE 6. Even as shown however,they do not interfere with stackability as already referred to, becauseeach super-posed chair would be laid upon the one below in reverserelationship.

Attached to each propelling handwheel rim, or to a spoke thereof, is aknob 37 (FIGURE 1). Thus, the operator may either use a rim type ofpropulsion similar to the present conventional wheelchair, or he may toadvantage maintain a constant drive by using the knob as a crank. Overlong distances or on ramps the knob drive is superior to theintermittent rim type drive. For small manoeuvers, the rims may be foundmore convenient. For frail patients, a mechanical advantage may besimply achieved by the selection of a larger sprocket 28 relative tosprocket 26.

The braking of the chair in the sense of reducing speed or bringing thechair to a stop is accomplished by applying hand pressure to therotating rims 25, this being similar to the present practice onconventional wheelchairs. Locking the chair in a fixed stationaryposition, however may be accomplished in one of two ways, the firstbeing illustrated in FIGURES 14 and 15 and referred to as the jackingmethod and the second FIGURES 3, 10 and 19 and referred to as thechain-locking method.

In the jacking method, a pair of brake levers 38 (FIG- URES 14 and 15)may be introduced between frames 4 and 8 (being commonly pivoted atpoint-s). Said levers are preferably joined by a tie bar 39. One end ofeach lever has a hand grip 40 and the opposite end, a rubber ferrule.When the brake is off the lever handgrip is in the lower position 41(FIGURE 15) and the lower end of the lever is clear of the ground. Whenthe lever is raised to position 42 its lower end makes contact with theground g1g2 and lifts the castors 10 slightly clear of the ground. Inthe fully raised position the lever passes over dead-centre and providesa stiff leg lock in this position against any suitable and obviousabutments (not shown). Thus the chair becomes very stable for entry orexit of the occupant.

The alternative chair-locking braking means is best shown in FIGURE 19which is a fragmented elevation through a portion of a stay frame 12. Alever 43 is attached to each end of a rod 44 which is coaxial withtubular tie bar 19 (FIGURE 3). The upper end 45 of lever 43' ispivotally connected to a dog 46 and said dog being horizontally slidablebetween a pair of guides 47 and 48 which span the space between stayframe tubes 29. Projecting teeth 49 on the dog may be brought intoengagement with adjacent links of drive chain 27 when the lever 43 ismoved in the direction of arrow 50. This effectively locks the chain andthus also the drive wheels. The lever 43 on either side of the chairlocks both wheels 11 simultaneously providing connecting rod 44 iscommon to both levers.

In general a great advantage is achieved by the small wheelconfiguration over conventional large wheel models by the elimination ofa rearward overhang which is out of the range of vision of the rider.Our wheelchair, therefore, describes a substantially smaller turningcircle and is therefore more manoeuverable in confined areas.

In general also it should be noted that although front castors and reardriven wheels is the preferred arrangement, the reverse is practical andwithin the general concept of our invention as illustrated in FIGURES 11through 13. The driven wheels when located at the rear should preferablybe as close to the vertical centreline of gravity of the accupant aspossible consistant with adequate stability. The reason for this is thatthe main mass of the occupant tends to pivot rather than swing in an arewhen negotiating turns. It will easily be perceived by reference toFIGURES 11 through 13 that on cambered roads especially, the ocoupantsmass when close to the castors will cause a sideways veering of thechair which is virtually eliminated by placing the drive wheels to theback.

What is claimed is:

1. A downwardly collapsible wheelchair, including a seat and back rest,characterised by upper and lower frames mutually pivotally connectednear the base of said chair in the vicinity of the ends of said frames,said lower frame carrying a pair of driven wheels which are of smalldiameter relative to conventional wheelchair driven wheels, and a pairof castors, whereby to provide a longer wheel-base and greater stabilitythan conventional wheelchairs, means spaced from said driven wheels foroperating the same, said upper frame including a pair of sidemembers ofwhich the upper corresponding portions of each are in permanent fixedrelationship conforming substantially to the angular relationship ofsaid seat and back rests of said chair when in seating position, andmeans for maintaining said chair in normal occupants seating positionagainst unwanted collapse.

2. The chair according to claim 1 which includes means for causing saidseat and back rest to assume a co-planar, substantially horizontal, andcontiguous relationship in the collapsed position of said chair.

3. The chair according to claim 2 in which said seat and back restoverlie said upper portion of said upper frame, and in which said upperframe, in the collapsed position of said chair, rests upon said lowerframe at the location remote from that of their pivoted connection.

4. The chair according to claim 1 in which said means for maintainingthis chair in normal occupant seating position against unwanted collapseincludes strut means pivoted in the vicinity of said driven wheels, andextending between said lower and upper frames, remote from their locusof pivoted connection, the upper ends of said strut means beingoperatively associated with said upper frame in the vicinity thereofwhich extends between the front and rear edges of said seat.

5. The chair according to claim 4 in which said means for maintainingsaid chair in normal occupant seating position includes foldable armrest assemblies comprising arm rests extending forwardly from said backrest, and link means pivotally connected in between said rests and saidstrut means, the rear ends of said rests being slidably associated withsaid back rest so as to move toward the upper ends of said back restwhile said link means move in a locking-toggle acute angularrelationship downwardly with the strut ends of said arm rest into anobtuse angular relationship, during the collapsing of said chair, whilesaid seat moves forwardly, and said back rest moves forwardly anddownwardly, as from the leading lower edge thereof into horizontalcoplaner relationship With said seat, and over said upper frame.

6. The chair according to claim 4 which includes a pair of occupantoperated hand wheels, and in which 8 v said strut means constituteelongated gear cases, gear means within said cases, said hand wheelsbeing operatitvely connected with said gear means for propelling said 0air.

7. The chair according to claim 1 in which said means for maintainingthe same in normal occupant seating position includes transverselyextending locking means located in the vicinity of the junction of saidseat and back rest.

8. The chair according to claim 1 in which said upper frame includes apair of side members the profile of each of which, as viewed in sideelevation, is seen to comprise lower portions inclining upwardly fromthe front of the chair towards the back, relatively horizontal portionswhich, in seating position, conform to the plane of, and lie contiguousto said seat adjacent the edges thereof, and upper portions which, insaid seating position, conform substantially to the plane of and liecontiguous to said back rest adjacent the edges thereof, said portionsof said side members being permanently fixed in their mutualrelationship, said seat and back rest being mutually hinged for movementbetween an angular seating and back supporting position, and ahorizontal co-planar position, at a lower level when said chair iscollapsed, at least a substantial length of said lower portions of saidside members lying parallel with and below said seat and back when thesame are in horizontal position, and means for locking said seat andback rest in seating and back supporting relationship.

9. The chair according to claim 8 which includes strut means pivotallyconnected at the lower end thereof to said lower frame in the axialvicinity of said driven wheels, said strut means maintaining said upperframe in normal seat supporting position, said seat resting upon saidseat supporting portion, and arm rest assemblies, said arm restassemblies including arm rests in slidable relationship to said backrest, and link means pivotally connected between said arm rests and saidstrut means, movable between lock-toggle acute angular relationship inthe seating and back-supporting position of said seat and back rest andunlocked obtuse angular relationship when said seat and back rest are inco-planar collapsed relationship.

10. The chair according to claim 1 which includes jackbraking levermeans in the form of at least one angulated bar pivotally connected tosaid chair in the vicinity of the front lower portion thereof androtatable between an out-of-use position in which the lower ends of saidbar is clear of the ground and a brake locking stiff-leg position inwhich said lower end is in ground pressing contact such as to lift saidcastors clear of the ground.

References Cited- UNITED STATES PATENTS 2,182,915 12/ 1939 Connolly.

2,592,025 4/ 1952 Gray 280-250 X 2,920,687 l/ 1960 Hurley 297-463,109,666 11/1963 Wilson 2-8036 X 3,137,511 6/1964 Weil et a1 297-ll'8 XKENNETH H. BE'ITS, Primary Examiner.

US. 01. X.R. 297-46;280- 36 r;

